A major problem which has retarded an analysis of neural development is a lack of suitable in vitro model systems amenable to experimental manipulation. As a step towards developing an in vitro model system to study cerebellar cell-cell interactions, we previously proposed to, and succeeded in establshing, a library of cell lines from the cerebellum which exhibit a differentiated phenotype. Here, we propose to undertake studies which will realize the use of these cell lines to analyze the development of the cerebellum on a molecular level. Specifically, the aims of this project are five fold: 1) to expand our collection of cell lines from the cerebellum so as to include lines representative of all cerebellar cell types, 2) to generate monoclonal antibodies which recognize antigens unique to specific cerebellar cell types, 3) to use the monoclonal antibodies to identify the cerebellar cell lines as to their in vivo cell counterparts, 4) to determine the relative intercellular adhesive specificities of the cell lines, and 5) to isolate the cell surface molecules involved in specific intercellular adhesion among the cell lines. As a result of these studies, it will be possible to perceive principles of neural development hitherto not accessible to in vivo experimentation. Thus this project may aid in understanding the basis for a variety of neural abnormalities which arise during early development.